The present invention relates to a reproduction signal processing technique of a magnetic recording and reproducing apparatus and, more particularly, to a reproduction signal processing apparatus and a reproduction signal processing method in which a partial response waveform process is included in an automatic equalization to correct a non-linearity of a reproduction signal.
A partial response waveform processing technique as a signal transmitting technique has been adopted in a recording and reproducing technique of a magnetic disk apparatus. Such a technique relates to a narrow band technique for converting one information into a plurality of sampling values. By using such a technique to the magnetic recording and reproducing apparatus, the band of a signal which is recorded onto a magnetic disk is compressed and recorded, and such a narrow band signal is discriminated by a plurality of threshold values. There has been a patent literature, JP-A-2-150114 regarding the partial response waveform processing technique, in which a method of correcting tap coefficients is disclosed.
Also, there has been a technical literature, JP-A-4-205903 to correct the non-linearity of a reproduction signal. As another technique literature to correct a reproduction signal, there has been a publication entitled "Adaptive Equalization in Magnetic-Disk Storage Channels", by J.M. Cioffi, IEEE Communications Magazine, pages 14-29, February, 1990.
It is an object of the present invention to provide a magnetic recording and reproducing apparatus, a reproduction signal processing apparatus, and a reproduction signal processing method in which an automatic equalizer executes not only an equalizing correction such that an automatic equalizer traces variation of equalizing characteristics of the equalizer but also an equalizing correction including a partial response waveform process.